Am having a hard time finding hydraulic TD head 1.6 L, am already using 1.9 L headgasket -can I use a 1.9 l Diesel head or 1.9 L TD head instead? I think Injectors are different, what other issues are there?
A 1.9TD head on a 1.6 may drastically lower compression. AFAIK I've only known of two 1.6 block / 1.9 head setups (one was mine) and they all smoked significantly at engine start.. however I had a modified head that lowered compression further and the other 1.9L head had a bent valve.
I'm not sure if a healthy 1.9TD head in a healthy setup will smoke much during cold start.
Injectors shouldn't be an issue.
Unless you're planning to nearly double the stock 1.6TD output (i.e. 130+hp), I would search for a 1.6TD head.